mohammad rahbar

Pseudomonas aeruginosa is a significant bacterium responsible for various infections. The increasing spread of antibiotic resistance in these bacteria is concerning. Key factors contributing to the rise in antibiotic resistance include the presence of integrons and the ability to form biofilms. The current study investigated the abundance of class 1 and 2 integrons and biofilm formation among clinical isolates of Pseudomonas aeruginosa in Tehran, Iran.
In this study, 100 clinical isolates of Pseudomonas aeruginosa were isolated. The samples were examined in terms of microbial and biochemical culture, molecular confirmation was done by PCR for OprL genes and the presence of class 1 and 2 integrons was checked. The significance of variables was checked with the p-value.
The prevalence of integron class 1 and 2 was 47% and 8%, respectively. Integron 1 and 2 were significantly higher in severe and moderate biofilm than in weak cases (P < 0.05). Out of 33 samples with strong biofilm, 90.9% of samples had the integron one gene. The results showed that the integron one gene was significantly higher in Multiple drug resistance (MDR) samples than in non-MDR samples (P < 0.05).
The relationship between biofilm formation and the presence of integrons shows the role of these factors in creating antibiotic resistance, and the presence of integrons 1 and 2 in clinical strains can increase the risk of drug resistance gene transmission.

Exudative diarrhea is a significant global public health issue, particularly affecting children under the age of 5. Identifying the cause of diarrhea is crucial for epidemiological surveillance and, in some cases, for ensuring appropriate treatment for patients.

The aim of this study was to investigate the frequency of bacteria responsible for exudative diarrhea in samples from children under five years old in a tertiary hospital in Iran.

In this multicenter cross-sectional descriptive study, 104 children with exudative diarrhea who were referred to Mofid Children's Hospital in Tehran, as well as hospitals in Hamedan, Ardebil, and Bandar Abbas, from December 2020 to March 2022 were enrolled. DNA extraction was performed using a commercial kit, and the identification of various causative bacteria was conducted through conventional and real-time PCR. Descriptive and inferential statistics were analyzed using SPSS version 22 software.

Most of the children with exudative diarrhea were under 12 months old (31%) or between 12 and 24 months old (22%). Boys made up 66% of the participants. Additionally, 70% of the children had a fever, and 58% experienced vomiting. Furthermore, 56% of the patients were dehydrated. The most prevalent bacterial causes of exudative diarrhea were Shigella spp., followed by Salmonella spp., Campylobacter spp., Clostridium difficile, E. coli-Stx1 , and E. coli-Stx2 .

The findings indicated that * Shigella * spp. was the leading cause of diarrhea in children under five years old. The most common signs and symptoms associated with exudative diarrhea were fever and vomiting, which physicians should consider in their diagnostic and treatment processes.

In the 2000s, some projects were defined to export Liquefied Natural Gas (LNG) in order to increase Iran’s presence in gas export markets.However, despite the initial planning until 2020, when this research was conducted, none led to a result, and Iran could not play a role in this market. Delay in executing these plans will lead to losing the opportunity to use the joint South Pars field and billions of dollars of foreign exchange earnings. The purpose of this study, which was conducted 2019 to 2020, is to identify the factors leading to the failure of Iran’s LNG projects. In order to identify and prioritize these factors, the opinion of experts and the Fuzzy Delphi technique is employed. Investigating the condition at the national and international level indicates that some factors have prevented all of these projects from being successful, including political issues, international sanctions on Iran, lack of domestic capital, lack of appropriate foundation for attracting foreign investors, constraints of domestic rules and regulations, especially in the upstream sector for choosing the contract format, not having access to the liquefaction technology, and the issues pertinent to marketing, and the most important one, lack of suitable commercial structural design. Identifying these factors and planning for tackling them is the key to escaping this current situation and a guide for prospering in future projects of the country.

 MRSA, or methicillin-resistant Staphylococcus aureus, has arisen as a nosocomial and community-acquired infection throughout the world. MRSA identification in the laboratory is difficult for a variety of reasons. The aim of this study was to investigate several phenotypic methods for the detection of MRSA compared with the PCR-based method as the gold standard.

 A total of 220 clinical isolates of S. aureus were recovered from diverse clinical specimens between August 1, 2019 and June 30, 2020 at Milad Hospital in Tehran, Iran. Cefoxitin discs, CHROMagar™ MRSA medium, and identification of the mecA gene by Polymerase Chain Reaction (PCR) as the gold standard method were used to assess methicillin resistance.

PCR testing revealed that 105 (47.72%) of 220 S. aureus isolates were positive for the mecA gene. The results of the Cefoxitin disc diffusion method showed that it has similar sensitivity and specificity to PCR method. The sensitivity and specificity of CHROMagar™ MRSA medium were both 100%. The Cefoxitin disc diffusion method had the same sensitivity and specificity as the PCR method for detecting the mecA gene. For MRSA detection, the Cefoxitin disc diffusion method can be employed as an alternative to PCR.

 Infections caused by Streptococcus pneumoniae (S. pneumoniae) have remained a significant public health concern worldwide. In developed countries, the highest prevalence of S. pneumonia has been reported among the elderly. The aim of this study was to evaluate the coverage of genotypes in the 13-valent pneumococcal conjugate vaccine (PCV-13) in the Iranian elderly population.

 A total of 41 isolates of S. pneumoniae were collected in the current retrospective cross-sectional study. The samples comprised 33 inpatients hospitalized for pneumococcal pneumonia and 8 outpatients. Multiplex polymerase chain reaction assay was performed to categorize the bacteria isolated into specific genotypes. Statistical analyses were performed using SPSS software, and the chi-square test was used to assess the statistical significance in percentages.

 A total of 68 genotypes were identified in this study, in which 39 isolates (57.3%) were associated with invasive infections. The most common genotypes were 6A/B [8 (19.5%)], 1 [7 (17.5%)], 14 [5 (12.2%)], and 19A [4 (9.75%)], respectively. The coverage rates of PCV-7, PCV-10, and PCV-13 vaccines were 51.17%, 70.7%, and 99.9%, respectively. According to our results, the pneumococcal coverage rate of PCV-7, PCV-10, and PCV-13 vaccine types is estimated to be 51.2%, 70.7%, and 99.9%, respectively. Furthermore, the trend of pneumococcal serotypes included in the PCV-13 was steadily increasing during the study period.

 It can be concluded that the most circulating pneumococcal serotypes were in accordance with specific serotypes included in the PCV-13 vaccine types. Therefore, including PCV-13 vaccines in immunization programs against pneumococcus in the elderly can effectively reduce the rate of infections.

Streptococcus pneumoniae remains a major cause of invasive streptococcal diseases among all age groups, particularly infants and the elderly.

This study aimed to recognize and determine S. pneumoniae serotypes isolated from clinical specimens by multiplex polymerase chain reaction (PCR).

A total of 105 pneumococcal strains were collected from nonvaccinated cases within the age range of 10 days to 92 years from five provinces of Iran within June 2017 to August 2019. The strains were cultured on blood agar. Biochemical analyses and molecular tests were performed for the primary identification of bacterial isolates. Capsular typing was carried out by multiplex PCR assay. Primers that target the capsular polysaccharide site were used in this study.

Out of 130 studied clinical specimens, 105 isolates of S. pneumoniae were detected and identified. The most frequently isolated capsular types were 6B, 14, 19A, and 1. Serotype distribution consisted of 83.5% of vaccine serotype and 16.5% of nonvaccine serotype. The serotype 6B was significantly more frequent (P < 0.05) among the invasive clinical isolates (75%) compared to that among their noninvasive counterparts (25%). The distribution of 13-valent pneumococcal conjugate vaccine (PCV-13) serotypes in invasive pneumococcal disease (IPD) and non-IPD revealed 83% and 84% of the isolated serotypes, respectively. Moreover, 83.5% of all the serotypes identified in the study were covered by PCV-13 serotypes.

The common serotypes of invasive and noninvasive groups in Iran are covered by PCV-13

Urinary Tract Infections (UTI) can depend on many factors such as bacteria, Escherichia coli and Klebsiella pneumoniae in particular. The high rate of carbapenem resistance in Enterobacteriaceae has become a global therapeutic problem.

The aim of this study was the investigation of OXA-23, OXA-24, OXA-40, OXA-51 and OXA-58 genes in uropathogenic isolates of E. coli and K. pneumoniae.

All 500 uropathogenic isolates of E. coli and K. pneumoniae have been segregated from patients at Milad Hospital, Tehran, Iran. Antibiotic susceptibility testing was performed using a strip-test method and the confirmation of carbapenem-resistant isolates were performed using an automated antimicrobial susceptibility testing system. OXA genes were determined by multiplex PCR assay. Moreover, molecular typing of isolates was performed by MLVA.

Out of 500 isolates, 40 (8%) isolates were detected as carbapenem-resistant, including 13 E. coli and 27 K. pneumoniae. All carbapenem-resistant isolates were ESBL-producing and resistant to ceftriaxone, ciprofloxacin, meropenem, ceftazidime and amoxicillin-clavulanate. Moreover, 46.1% and 26% of carbapenem-resistant E. coli and K. pneumoniae isolates had a gene encoding β-lactamase associated with the OXA-23-like group. E.coli and K. pneumoniae isolates were divided into 2 and 3 MLVA patterns, respectively.

This is the first report of OXA-51, 58 and 24 carbapenemases in clinical isolates of E. coli and K. pneumoniae isolated from urinary tract infections in Iran. Significant differences in OXA-51, 58 and 24 genes were found in carbapenem-resistant and carbapenem-susceptible E. coli and K. pneumoniae isolates. Molecular typing of isolates has suggested vertical transmission of resistant genes.

To have a strong presence in the gas export market during the 2000s, Iran had designed projects to export more than 70 million tons of LNG per year. If these plans came to fruition, Iran would now be one of the largest exporters of LNG in the world. But so far, none of these projects have been put into operation, and with the existing conditions in the future, it will not be possible to use them. This delay represents a loss of access to South Pars' shared resources and millions of dollars in foreign exchange earnings. Failure to use a proper business structure as a reason for past projects' failure shows the need for structural reform.The purpose of this study, which was conducted from 2019 to 2020, is to identify the optimal structure for the country's projects. In this regard, by evaluating a wide range of criteria by experts in the oil and gas industry and using the ELECTRE-TRI technique, we classify the existing structures and introduce the optimal structure. The results show that the optimal structure will be achieved by using the IPC contract in the upstream sector and combining it with the participation of the upstream partner in the construction of the liquefaction facility. This structure, by the domestic laws and regulations and by attracting foreign investors by ensuring a long-term presence in the upstream and downstream sectors, can counteract international sanctions, increase efficiency, and speed up the implementation of projects. Provide.

Due to frequent exposure to surface water and contact with animals, children represent a group susceptible to zoonotic diseases.

The present study aims to determine the presence and prevalence of the main zoonotic agents in R. norvegicus populations in Tehran, Iran.

In the present study, 100 R. norvegicus were captured within a time span of one year from five districts of Tehran, Iran. Fecal and blood samples were collected from rodents and serum was recovered after centrifugation. The presence of specific IgG antibodies against Leptospira spp. and Rabies virus was detected using a commercial qualitative rat ELISA kit. A conventional PCR assay was employed to detect the presence of Vibrio vulnificus in the commensal R. norvegicus population.

In general, 80% (n = 80/100) and 20% (n = 20/100) of rats were males and females, respectively. The results of the ELSA assay showed that of the 100 R. norvegicus captured in Tehran, 7% (n = 7/100) and 1% (n = 1/100) were positive for Leptospira spp. and Rabies virus, respectively. Leptospira spp. revealed the highest frequency (20%; 4/20) among R. norvegicus collected from the eastern part of Tehran. Rabies virus was detected only from the southern (5%; 1/20) part of Tehran. Results of the PCR method showed that the percentage of the rats tested positive for V. vulnificus was 5%. Overall, the surveyed zoonotic microorganisms had the highest (n = 5/20; 25%) and lowest (n = 1/20; 5%) frequency rates in the eastern and northern parts of Tehran, respectively.

The results accentuate the necessity of implementing rodent control programs and regular disinfection as well as avoiding contact with rodent populations in urban environments.

One of the most critical concerns in Klebsiella pneumoniae isolated from nosocomial infections is antibiotic resistance due to transferable resistance genes. This study aims to investigate the relationship and role of integrons in the transport of OXA-type genes in the production of carbapenem-resistant isolates.

In this study, 270 isolates of K. pneumoniae were isolated from patients with urinary tract infection symptoms hospitalized at Milad hospital of Tehran during 2017-2018. The biochemical methods confirmed K. pneumoniae isolates. Also, antimicrobial susceptibility testing was performed using an E-test method. Carbapenem-resistant isolates were confirmed using an automated antimicrobial susceptibility testing system (Phenix BD USA). The presence of OXA genes, integron, and its class were determined by PCR method.

According to our findings, the most effective antibiotics against uropathogenic K. pneumoniae isolates were piperacillin-tazobactam and meropenem, respectively. Out of the 270 isolates, 27 (10%) were detected as carbapenem-resistant K. pneumoniae isolates. Moreover, 47.2%, 40.1%, 39.2%, and 36.4% of K. pneumoniae isolates were resistant to ceftriaxone, ceftazidime, trimethoprim-sulfamethoxazole, and amoxicillin/clavulanate, respectively. A significant proportion of isolates had class I integron. Meaningful differences in OXA-51, 58, and 24 genes were found in carbapenem-resistant and carbapenem-susceptible K. pneumoniae isolates. No significant relationship was observed between class 1 and 2 integrons and other studied gene determinants of antimicrobial resistance.

According to the observed results, OXA-23, OXA-24, OXA-58, and OXA-51-like groups were the most prevalent genes in carbapenem-resistant K. pneumoniae isolates, respectively. Also, 97.9% of carbapenem-susceptible K. pneumoniae isolates had class 1 integron.

This study aims to define S. pneumoniae serotypes in children hospitalized with an invasive pneumococcal disease from March 20, 2012 to March 10, 2013 by polymerase chain reaction (PCR) method.

Specimens from cerebrospinal fluid and blood were collected from children aged one month-18 years with suspected invasive pneumococcal infection admitted to Mofid Children’s Hospital and other regional hospitals. Multiplex PCR with 13 groups of primers were used to detect 33 serotypes of S. pneumoniae in positive blood and cerebrospinal fluid cultures. Out of 563 samples, 83 S. pneumoniae isolates were identified. Sixty-seven samples were typeable.

The results showed that serotypes 3 (21.7%), 23F (13.2%), and 19F (10.8%) were the most prevalent serotypes. Sixteen samples (19.3%) were non-typeable by Multiplex PCR method. The 13-valent pneumococcal vaccine provides the highest coverage (66.23%), followed by the 10-valent vaccine (34.9%) and, lastly, the 7-valent vaccine (33.71%).

We found that serotypes 3, 23F, and 19F accounted for almost 46% of invasive pneumococcal isolates. As per relatively high coverage of prevalent serotypes, PCV13 should be considered for routine childhood vaccination programs.

Strain subtyping is an important epidemiological tool to trace contamination, determine clonal relationships between different strains, and the cause of outbreaks. Current subtyping methods, however, yield less than optimal subtype discrimination. Pulsed-field gel electrophoresis is the gold standard method for Escherichia coli and Multiple-Locus Variable-number tandem repeat Analysis is a rapid PCR-based method. The purpose of this study was to evaluate MLVA and PFGE methods for subtyping β -lactamase-producing E. coli strains isolated from urinary tract infections. Overall, 230 E. coli isolates from patients with urinary tract infections were examined for antimicrobial susceptibility testing.   10-loci and 7-loci MLVA and PFGE methods were used for molecular typing of β -lactamase-producing E. coli isolates. Out of 230 isolates, 130 (56.5%) β -lactamase-producing E. coli isolates were found in this study. The diversity indices of the VNTR loci showed an average diversity of 0.48 and 0.54 for 7-loci and 10-loci MLVA, respectively.  The discriminatory power of PFGE showed a value of 0.87. The discordance between the methods was high. Our study showed that PFGE is more discriminatory than MVLA.  MLVA is a PCR- based method and can generate unmistakable data, in contrast to PFGE. Optimization of polymorphic VNTR is essential to improve the discriminatory power of MLVA based on geographical region.

As a global health pandemic, the novel severe acute respiratory syndrome-coronavirus 2 (SARS- CoV2) outbreak began in December 2019 which rapidly spread to more than 200 countries. Respiratory complications and fever are the most obvious symptoms. Sometimes the neurological features are superimposed on the main disease and complicate patientchr('39')s status.

We describe 6 patients with COVID-19 and concomitant quadriparesia who underwent electrodiagnosis using EMG/NCS and results indicated 3 axonal variants of Guillain–Barré syndrome (GBS), including; 2 cases AMAN (acute motor axonal neuropathy), 1 case AMSAN (acute motor and sensory axonal neuropathy), three myopathies, including one combination of CIN/CIM (critical illness neuropathy/critical illness myopathy), one CIM and one acute polymyositis in these cases.

Early diagnosis of the neuromuscular disorders of coronavirus could help for correct planning in the treatment of COVID-19 patients. Since GBS and inflammatory myopathies have an autoimmune basis, the immunotherapies such as IVIG, steroids, plasma exchange and other novel treatments as hemoperfusion can promise better and faster recovery in respiratory function and neuromuscular activity among COVID-19 patients who have musculature paralysis concomitantly. However, all these treatments are challenging and further clinical trials should be done to confirm the efficacy and safety of mentioned therapies.

β -lactamase -producing E. coli is the most important agent causing   urinary tract infections both in community and hospitals. Strain typing including MLVA and PFGE are the most common epidemiologically   tools not only for detecting the cross transmission of nosocomial pathogens but also for determining the source of infection.

The present study was carried of for comparison of discriminatory power of MLVA and PFGE methods. A Total of 230 isolates of E. coli from patients with urinary tract infections were examined for identifying and antimicrobial susceptibility testing MLVA and PFGE methods were used for molecular typing of all isolates.

Out of 230 isolates, 130 ( 56.5%) β -lactamase -producing E. coli isolates were found in this study. The diversity indices of the VNTR loci showed an average diversity of 0.48 and 0.54 for 7-loci and 10-loci respectively. The discriminatory power of PFGE showed a value of 0.87.

Our study showed that PFGE is more discriminatory than MVLA. MLVA is a     PCR- based method and generates unmistakable data, in contrast to PFGE. Optimization of      polymorphic VNTR is essential to improve the discriminatory power of MLVA basis on  geographical region.

AmpCβ-lactamases are capable of hydrolyzing all β-lactams except cefepime and carbapenems. The detection of AmpC-producingEscherichia colihas a high priority in infection management. This research is aimed to investigate the resistant AmpC-generating E.coliisolates and identify their genetic variety.

In this study, 230 E. coliisolates from patients having urinary tract infection symptoms were investigated in 2017-2018 to assess their susceptibility toward antimicrobial agents. AmpC genes were evaluated by PCR and molecular typing using the 10-loci MLVAmethod. MLVA images were examined by BioNumerics 6.6software through the use of the UPGMA algorithms.

The highest frequencies of susceptibility among E. coliisolates were to meropenem 96.08%, piperacillin-tazobactam 90.43%, followed by gentamicin 66.54%, ceftazidime 50%, ciprofloxacin 48.26%, ceftriaxone 41.74%. All E. coliisolates were resistant to amoxicillin-clavulanate. Thirty-eight AmpC-generating E. coliisolates were detected. The most abundant determinant was CIT and EBC, FOX,and DHAhad the next ranks, respectively. Six major clusters and a singleton were identified by MLVA.

AmpC-generation ability is an effective feature in the resistance of E. coliisolates and its investigation is of crucial significance in infection management. The major mechanisms of AmpC beta-lactamase vary depending on time and geographical location

Toxigenic Clostridium difficile is one of the prevalent diarrheagenic pathogens in hospitalized patients.

The study assessed the ability of three diagnosticmethods in identifyingC. difficile strains. The genotyping of the isolates was done, as well.

Stool samples were subjected to three different diagnostic methods including direct stool culture, glutamate dehydrogenase enzyme immunoassay (GDH-EIA), and direct stool PCR for the detection of the tcdA andtcdB genes. The sensitivity and specificity of the tests were evaluated. The genotyping was done by the PFGE method.

Of 120 samples, 20 (16%) were positive for C. difficile based on PCR, while 15 (12.5%) and 12 (10%) were positive according to GDH-EIA and direct stool culture. Among patients with C. difficile-associated diseases (CDAD), 11 (61%) were more than 65-years-old. The specificity of PCR, GDH-EIA, and direct culture was almost similar and equal to 100%, but their sensitivity was 90%, 70%, and 60%, respectively. The positive predictive value (PPV) was lower for GDH-EIA than for the other two methods, and the highest negative predictive value (NPV) was related to the PCR method. The results showed a high similarity between the isolates, and only were three pulsotypes differentiated among the isolates.

The specificity and sensitivity of the direct stool PCR method were higher than those of the other two methods. Although PCR inhibitors may reduce its ability for the correct diagnosis of negative samples, it seems to be a reliable method for the detection of C. difficile infection. The weakness of the GDH-EIA method was its lower PPV, which can cause false-positive results. Toxin patterns and pulsotypes of C. difficile isolates revealed a high similarity between the strains isolated from the same units.

Toxigenic Clostridium difficile is one of the prevalent diarrheagenic pathogens in hospitalized patients.

The study assessed the ability of three diagnostic methods in identifying C. difficile strains. The genotyping of the isolates was done, as well.

Stool samples were subjected to three different diagnostic methods including direct stool culture, glutamate dehydrogenase enzyme immunoassay (GDH-EIA), and direct stool PCR for the detection of the tcdA and tcdB genes. The sensitivity and specificity of the tests were evaluated. The genotyping was done by the PFGE method.

Of 120 samples, 20 (16%) were positive for C. difficile based on PCR, while 15 (12.5%) and 12 (10%) were positive according to GDH-EIA and direct stool culture. Among patients with C. difficile-associated diseases (CDAD), 11 (61%) were more than 65-years-old. The specificity of PCR, GDH-EIA, and direct culture was almost similar and equal to 100%, but their sensitivity was 90%, 70%, and 60%, respectively. The positive predictive value (PPV) was lower for GDH-EIA than for the other two methods, and the highest negative predictive value (NPV) was related to the PCR method. The results showed a high similarity between the isolates, and only were three pulsotypes differentiated among the isolates.

The specificity and sensitivity of the direct stool PCR method were higher than those of the other two methods. Although PCR inhibitors may reduce its ability for the correct diagnosis of negative samples, it seems to be a reliable method for the detection of C. difficile infection. The weakness of the GDH-EIA method was its lower PPV, which can cause false-positive results. Toxin patterns and pulsotypes of C. difficile isolates revealed a high similarity between the strains isolated from the same units.

Knee osteoarthritis (KOA) is the most common degenerative joint disease resulting in bone pain and disability. The aim of current study is to determine diet quality by healthy eating index (HEI)-2015 in association with pain and functional status among a sample of participants with primary knee OA.

In this cross-sectional study, 220 patients with knee OA were recruited via convenience sampling in the outpatient clinics of Tabriz University of Medical Sciences between April and September 2018. The HEI-2015 score was calculated from dietary data collected using a Food Frequency Questionnaire (FFQ). Visual analogue scale, Western Ontario and McMaster Universities Osteoarthritis Index and the SF36 quality of life (QoL) questionnaire were applied to measure the pain intensity, functional status and QoL in the participants, respectively. Participants were categorized based on the quintile cutoff points of HEI score including 42-62, 63-69, 70-75, 76-78 and 79-100.

The mean score of HEI was 70.62±10.18 (range: 42–89). Participants with greater HEI2015 scores had higher total energy intake (P=0.008) and greater dietary intake of carbohydrates (P=0.01), protein (P=0.009), monounsaturated fatty acids (P=0.01), polyunsaturated fatty acids (P=0.007) and fiber (P=0.009) and lower intake of saturated fatty acids (P=0.005). Participants in higher quintiles of HEI had significantly lower pain intensity (P=0.001) and higher scores of physical function (P=0.001), pain (P=0.001) and role limitation due to physical problems (P=0.005) subscales of SF-36 QoL questionnaire in comparison with participants in lower quintiles of HEI-2015.

The HEI-2015 score is associated with pain intensity and two domain of QoL in patients with knee OA.

Colonization rate of Acinetobacter baumannii is increasing in hospitalized patients especially in long term hospitalized one and / or who were treat with extended spectrum antibiotics or anticancer. Antibiotic resistance in A. baumannii is considerable because more prevalence of them cause nosocomial infections and can impose high cost to health systems and patients. The aim of this study was determination of tigecycline, minocycline and colistin resistance A. baumannii in selected center in Tehran, Iran. 

This study was descriptive and functional foundation. In this study A. baumannii were collected from Milad, Mofid, Taleghani, Motahari and Loghman hospital, Tehran and transferred to laboratory of pediatric infections research center. Collected bacteria were identified by conventional microbiology tests. Antibiotic susceptibility testing was determined according to CLSI guide line. Tigecycline, minocycline and colistin resistance strains were isolated.  

In this study, 105 A. baumannii were collected from five selected hospitals: 48 (46%) from Milad, 33 (31%) from Motahari, 17 (16%) from Loghman, 4 (4%) from Mofid and 3 (3%) from Taleghani hospital. The highest resistance was observed against cefepime and high frequency of carbapenem and minocycline was observed. On the other hand, observed resistance to aminoglycosides was 93% at least. Tigecycline is the most effective antibiotic after colistin. Colistin resistant confirmed just in one isolate by E. test.

The results of this study indicated that high rate of antibiotic resistance in A. baumannii even resistant to third and fourth generation of cephalosporin and carbapenem antibiotics. The treatment of MDR strains of A. baumannii become more complicated if the spread of them were not been controlled.

The first imipenem-resistant A. baumannii emerged shortly after the introduction and therapeutic use of carbapenems, particularly imipenem. The resistance to imipenem in this strain was found to be associated with oxa23 which is the most widespread gene conferring resistance to carbapenems. Because of the wide distribution of oxa23 in Iranian isolates, identifying the genotypes of endemic or circulating isolates in hospitals is of prime importance. This study aimed to identify the genotypes of carbapenem resistant A. baumannii isolates carrying oxa23 recovered from clinical specimens in selected hospitals of Tehran.

A set of 92 A. baumannii isolates was collected and identified. Antibiotic susceptibility testing was performed by disk diffusion. A multiplex PCR was done for screening oxa23, oxa24 and oxa58 genes. The genetic pattern of the isolates was identified by Pulsed Field Gel Electrophoresis (PFGE) using ApaI enzyme.

Of the 92 isolates, 81 (88%) harbored oxa23. In the current study, 72 distinct pulsotypes were identified and of them 61 pulsotypes contained only one isolate while in the remaining 11 pulsotypes, two or more isolates were clustered.

This study showed the polycloncal distribution of the carbapenem resistant A. baumannii isolates carrying oxa23 in selected hospitals. Some of the isolates carrying oxa23 were detected for several months in target hospitals.

The aim of our study was to investigate mechanisms of aminoglycoside resistance in extended-spectrum beta-lactamases (ESBL)-producing Klebsiella pneumoniae (K. pneumoniae) isolates from Iran. To this end, 154 clinical isolates of K. pneumoniae were collected from two hospitals in Ilam city, Iran. The Kirby-Bauer (agar diffusion) antibiotic testing method was used to determine the susceptibility pattern of the isolates against kanamycin, gentamicin, tobramycin, netilmicin and amikacin. Aminoglycoside acetyltransferases (aac(3)-IIa, aac(6’)-Ib, and aac(3)-Ia), 16SrRNA methylase genes (armA and rmtB) and ESBL genes (blaTEM, blaSHV, and blaCTX-M) were detected by PCR amplification. 59.1% (n = 91) of K. pneumoniae isolates were detected ESBL producers with the phenotypic test. Moreover, blaTEM, blaSHV and blaCTX-M were detected in 83.5% (n=76), 52.7% (n=48) and 26.4% (n=24) of the ESBL-producing isolates, respectively. Among 52 resistant or intermediate isolates against aminoglycosides, the aac(3)-IIa, aac(6’)-Ib and rmtB genes were detected in 55.8% (n = 29), 80.8% (n = 42) and 1.9% (n = 1) of the isolates, respectively; none of the isolates, however, had the aac(3)-Ia and armA genes. Therefore, the results showed the high prevalence of aminoglycosides resistance in the K. pneumoniae isolates. As observed, the acetyltransferase modifying enzymes (aac genes) played major roles in determining this resistance. However, the rate of 16srRNA methylase genes was extremely low in K. pneumoniae.

The preoperative identification of patients who might need constrained condylar knee (CCK) prosthesis in total knee arthroplasty (TKA), is essential to ensure the availability of equipment and to address the patients’ expectations accurately. 

In this study, we aimed at investigating if the preoperative features of the patients can provide this data.

A total of 30 patients who underwent primary TKA for severe osteoarthritic genu varum deformity (varus angle ≥20º) were evaluated in this retrospective study. Prosthesis selection was based on preoperative and intraoperative information. Demographic data, preoperative correctability of the deformity, and intraoperative information, including the reduction osteotomy, soft-tissue release, and pie-crust technique, were retrospectively collected. Soft-tissue release was performed in a sequential manner in 3 steps.

The study population included 4 males and 26 females with a mean±SD age of 64.6±8.7 years. A CCK prosthesis was used in 11 (36.7%) cases. A significant association was found between the preoperative correctability and the type of prosthesis. In other words, all CCK prostheses were used in patients who were preoperatively non-correctable (P<0.001). Also, the step of release was significantly associated with the type of prosthesis, and CCK prosthesis was used in all patients with step 3 release (P<0.001). Preoperative correctability was significantly related to the step of release, as well. It means that all deformities with step 3 release were preoperatively non-correctable (P=0.008).

Antibiotic resistance in Vibrio cholerae is a crucial matter in the world. Objective of this study was the improvement of cholera surveillance by assessing the antimicrobial resistance pattern and bacterial  resistance genes in V. cholerae O1 isolates, reffered to Iranian Reference Health Laboratory, in cholera outbreaks during 2012- 2015.

This study is a cross sectional- descriptive research. Antimicrobial susceptibility test (AST) to 8 antibiotics was performed on 113 V.cholerae O1 isolates using E-test method. For all isolates, conventional PCR method was used to detect the presence of tetracycline resistance genes (tetA, tetB and tetC) and the sulfamethoxazole-trimethoprim resistance genes (sul2 and dfrA1).

All isolates were sensitive to ampicillin, temocillin, ciprofloxacin and cefixime and 64% of strains showed intermediate susceptibility to erythromycin. The resistance rate of nalidixic acid, sulfamethoxazole-trimethoprim and tetracycline were 90%, 71% and 50% respectively. However, the frequency of multidrug resistant (MDR) strains varied across the years. The frequency of resistance genes (tetA, tetB, tetC, sul2 and dfrA1) were 70%, 34%, 58%, 66% and 70% respectively.

AST should be used to determine the resistance profile at the beginning of a cholera outbreak and to monitor the resistance profile of circulating strains as part of surveillance of the disease. A prominent association was observed between phenotypic resistance to sulfamethoxazole-trimethoprim and presence of dfrA1gene. Determining the presence of resistance genes is necessary for understanding the epidemiology and routes of transmission of antibiotic resistance genes

Gram-negative bacteria are a major cause of pulmonary infection in patients with cystic fibrosis (CF). The study aimed to conduct the molecular identification of Gram-negative bacterial flora causing pulmonary infection in children with CF. In this study, sputum samples were taken from 64 CF children undergoing treatment as outpatients or inpatients at a referral children’s hospital in Tehran. The PCR technique was used to detect the presence of Gram-negative bacteria, namely Pseudomonas spp., Acinetobacter baumannii, Stenotrophomonas maltophilia, and Burkholderia cepacia. All samples were positive for 16srRNA. Pseudomonas spp. and A. baumannii were detected in 47% and 14% of the studied samples, respectively. Co-colonization by Pseudomonas spp. and A. baumannii was observed in three (5%) samples. According to this survey, Pseudomonas spp. were the most prevalent Gram-negative bacteria isolated from CF patients with pulmonary infection by molecular assays.

 Capsular polysaccharides of pneumococci are principle antigenic constituents of vaccines against pneumococci. Enhancing the yield of capsule production decreases costs of these vaccines and increases the vaccine coverage in developing countries. In this study therefore, we aim to optimize the capsule production from serotype 19F pneumococcus in terms of the applied pneumococcal strain and environmental culture conditions.  Thirteen serotype 19F Streptococcus pneumoniae strains were screened for the capsule production in modified Hoeprich culture medium using the stains all assay. The optimal ranges of environmental culture conditions for the selected strain were determined using single factor at a time (SFAT) strategy and utilized for the design of experiments based on the response surface methodology (RSM).  S. pneumoniae 82218 showed the highest capsule production, and thus used for further studies. The maximum capsule production (1.364 mg/ml) was attained under optimal conditions (pH 7.26, 35.5 ºC, 30 rpm) predicted by the RSM derived quadratic model. The capsule production under the optimal conditions increased to 1.9 mg/ml using the buffered culture medium.  These results are much higher than those reported for pneumococcal capsule production in published studies [1, 2] and thus can be used to design suitable systems for the serotype 19F capsule production in the vaccine manufacturing process.